The 37-year-old programmer and entrepreneur has been capturing and archiving every public Web page since 1996.

His nonprofit Internet Archive serves as a historical record of cyberspace. His for-profit company, Alexa Internet, uses the archive as part of an innovative search tool that lets users call up "out-of-print" Web pages. 2 MONTHS TO CAPTURE

From a 100-year-old, red-roofed office in the Presidio, Alexa's 32 employees send out computer programs that crawl the Internet to find and download Web pages. It takes about two months to capture the entire Web -- currently some 300 million pages.

Along with the actual pages, the programs retrieve and store "metadata" -- information about each site, such as how many people visited it, where on the Web they went next and what other pages are linked to it.

The Web pages are stored digitally on a "jukebox" tape drive the size of two soda machines. It contains 10 terabytes of data -- as much information as one-half the entire Library of Congress.

Like that institution, the Internet Archive doesn't exclude information because it's trivial, dull or just plain weird.

A VIRTUAL LIBRARY

"Of course, we've got more pictures of Cindy Crawford than the Library of Congress does," said Kahle. But to create an accurate portrayal of our life and times, it's necessary "to capture all the dreck you could ever want."

Having created a virtual library, the next step was to make a better card catalog. So Kahle and partner Bruce Gilliat started Alexa, named after the ancient Library of Alexandria.

Alexa's search engine uses the Archive's metadata to help users find information based on the trails of other Internet surfers.

The search engine, available for free at www.alexa.com, is a toolbar that sits along the bottom of a Web browser. It looks at the site a user is currently viewing and suggests other pages by analyzing where previous visitors to that site went next.

OLD SITES TO VIEW

What separates Alexa from other search engines is that it lets users view sites that have been removed from the Web.

When they encounter the message "404 Document Not Found" users can click on the Alexa toolbar to fetch the out of print Web page from the Internet Archive.

Alexa is supported by advertising, but even the ads relate to users' interests. A visitor to the Amazon.com Web site might see a Barnes & Noble ad.

"Clearly we need better tools for exploring the Web," says Peter Lyman, head librarian for the University of California at Berkeley and an Internet Archive board member. "Alexa is trying to help us find our way out of the forest by looking for trails where previous people have gone. It's the most promising idea about how we'll search the Internet in the future."

GRANDER PLANS

Available since September, Alexa already has 100,000 users but Kahle has grander plans for it.

"Our goal is to make this part of the infrastructure of the Internet," he said.

One surefire way to achieve that status would be to sell Alexa to a browser company, a search engine company or a major Internet service provider -- any of which might be a possibility, Kahle said.

Browser and search firms are snapping up technology that improves Web navigation. Search company Lycos last week spent $39.75 million for WiseWire, which automatically organizes Internet content into directories and categories. Last month Microsoft shelled out a reported $40 million for Firefly, which recommends content to Web surfers based on profiles they submit.

Kahle already has a track record of creating next-step Internet technology. In the early 1990s, he developed the Wide Area Information Server (WAIS), the first system for publishing quantities of data in a searchable form on the Internet.

IMPRESSIVE BACKGROUND

Besides an impressive programming background, which includes a degree from the Massachusetts Institute of Technology and a stint designing supercomputers at Thinking Machines Corp., Kahle has an abiding interest in traditional media.

His hobby is letterpress printing. Painstakingly aligning individual lead letters by hand to make cards and documents is a far cry from computer automation, "but that's the charm," he said.

TYPE DESIGNER'S LEGACY

They named their 3 1/2-year-old son Caslon after an 18th century type designer. Their 9-month-old son Logan has a family name.

"When the printing press came about, it fostered thousands of tiny presses all over the globe, allowing people in small towns to publish and distribute information. That's what we're finding here on the Web," he said.

"As we move human knowledge from paper to computers, people are getting access to huge amounts of information more easily. But to help organize the Web we have to track what's on it and what's going on over time."